Thread: Regrounding the O2 Sensor

Well it was fairly interesting, with spark plugs I saw results instantly. It was 1-3 MPG differences!

I will keep the Battery unplugged for 30 minutes, Never heard of reseting the TPS like that, but will do that.



Ohh, well big thanks for the information . Solder is usually pretty good until the wire has to move a bit then the solder will crack and might brake off.

Spark plugs are really apart of the ignition system. The O2 sensor is on a different mgmt system, emission system. But you still might get immediate changes.. Thats why we test for results.

Dont know where the eBay guy gets his parts (probably remags) but the connectors are not the normal Bosch Universal connectors. And due the heat & vibration, a solder joint will not hold up over time. I would use the Bosch connector if available.
Hopefully, the wires are long enough to overcome the heat.

Ahh yeah true, with emissions it needs to get enough reading etc...

I'm thinking maybe from some other country? Searching for what seems like the model number rendered me couple pages that were in Russian!

The wires are pretty long, almost as long as stockers, so it should be fine

You only need 6-8 inches to escape the header heat but the vibrations is always there with the engine shaking.

Yep, Ive been on the English site, French site, Dutch site and alot of time on the Aussy site.. The Aussy's have done alot of detail research trying to fix the SR20 bogging issues and idle issues. But, they have not solved those problems either. Im planning to look on the Japenese sites but I always have problems with the translations on their site (same problems with German sites).

Your eBay O2 sensor should be fine. But now you need two of them. Btw, can you PM me some more pictures of the internal grounding connection showing the opposite side where the external thread section comes into contact with the grounding connection. I have a few spare O2 units and I want to perform some tests at the actual grounding connection point.

Oh it's def longer then 8"

I crimped them, don't really trust solder in the bay anymore

Why would I need two of them? For the rear one? I can't get the rear one unscrewed, it looks like a common issue with our 99 cars.

I didn't get a chance to take any pictures, but basically it is connected to the tip where the wires just enter the O2 sensor... Pretty much the silver part on the O2 sensor in the first picture below:

Status update, it is hooked up, my alternator came in today, I unscrewed the old one, but didn't have time to take it out.

(Tight clearance with the fan, I'm considering a thinner fan)



(Connected with a good old zip tie )


(Ground Wire coming from the sensor and running up to the Intake Mani)



Connections to the left, this is where my MAF and O2 sensor is grounded at, now when I was doing that I noticed that I did ground my MAF by my battery. I still got a good low voltage, but just to be safe the MAF is now on the ECU ground

Great!! Now the ECU, MAF & O2 is on the same ground. Reset the ECU. You should see improvements.

Question: So, you are not using the rear O2 sensor? Wont that trigger a CEL?
Your OBII ECU is looking for the signals for fuel mappings. Your system is designed for 2..

Oh trust me the ECU has been reset for sure, the car has been sitting without battery power for a while haha.

I want to be using the Rear O2 sensor, but it is hard stuck to the cat, there is no way to get it off!

That does trigger a CEL on our cars. Now the Rear O2 sensor is only there to see if the CAT is working fine or not. It does not do anything, thats why I don't want to waste money another one too.


Now, on the old forum I remember reading something interesting. If you have a CEL, the ECU goes into Open-loop/failsafe mode, so a lot of gas gets wasted then.


Link to that post

So, for now I will see if the Front O2 sensor gives me better MPGs, then I will fix the CEL, with either a resister or a new O2 sensor for the back. Then I will test if the CEL theory is true.

If it is, then everyone with a CEL who wants better MPG's will need to fix all their problems before they can achieve it.

Flare-nut style crows foot and a breaker bar, but you have to do it when the exhaust is hot.

Yeah...

This pretty much brings to the same issue that Sentrixx posted about.

Heat is the key to removal of the rear O2 sensor.. Yes, this will impact your gas mileage as the ECU trim adjustments are made based on the quality of exhaust after the CAT is compared to the 1st O2 sensor readings... This sucks... As you will probably need to apply the resistor patch (if it works) or get another O2 sensor...

Looks like I need to buy the O2 sensor after all. I found one for $55 after calling around but I need to make some more calls.